Machinery of all kinds require adequate lubrication to prevent premature wear and/or failure. It is well known that machine operators are required to lubricate moving parts of machines in order to allow them to continue to function without undue wear. In fact, it is likely that proper lubrication is the most important aspect of machine maintenance in normal usage patterns.
There have been numerous inventions which address a need for lubricants to machine parts; see e.g. U.S. Pat. No. 3,719,254 to Snider; U.S. Pat. No. 3,807,530 to Fodali; U.S. Pat. No. 4,896,596 to Helinski; U.S. Pat. No. 5,307,902 to Herrmann et al; and U.S. Pat. No. 5,460,243 to Patterson. Helinski discloses a lubrication system for print hammer mechanisms including channels along the length of the pivot pin which are filled with a porous material containing an oil lubricant. Lubricant is conveyed to the interface between each print hammer element and the pivot pin by capillary action which transfers oil from a principle reservoir. Herrmann et al disclosure an improved shaft lubrication method including a plate of porous material forming capillary passages for the transmission of a lubricant through the shaft from a lubricant reservoir which communicates with the porous material.
Additional references including U.S. Pat. No. 4,175,642 to Bianchi et al; disclose further pass of lubrication methods where surfaces to be lubricated are supplied with lubricating oils by communicating with a reservoir filled with a porous matrix impregnated with oil. U.S. Pat. No. 3,367,445 to Dryden discloses a fluid lubrication system including a porous material containing an oil reservoir in proximity with the face of a bearing or a gear. However, Dryden taught that it was necessary to leave a small gap between the moving part to be lubricated and the porous metal material used to provide the lubricant in order to avoid wear on both the porous material and the moving part. Dryden relies upon capillary action to replenish the oil and centrifugal force to distribute the lubricant on the face of the gear.
U.S. Pat. No. 2,704,465 to Haller discloses a self-lubricating wheel such as a cog wheel, gear, sprocket wheel, rachet wheel, cam or the like. The wheel is made of sintered metal material which contains pores which are reported to allow oil to pass from an internal lubricant reservoir to the external surface to provide a metered amount of lubricant to the "teeth" or "lobes" of the wheel so that a film of lubricant is always present on these teeth without either being excessive in quantity so as to attract dust and other debris, or insufficient in quantity so as a result in inadequate lubrication. In spite of the lubrication provided by the sintered metal wheel, however, it is likely that the metal surface of the wheel would act to abrade surfaces with which it interacts.
Microporous synthetic resin or polymeric matrix materials to incorporate a fluid such as an ink or an oil lubricant have been known for some time. U.S. Pat. No. 3,055,297 to Leads discloses such a microporous synthetic resin material containing non-solvent organic liquid such as alcohols, glycols, petroleum ether, esthleen, mineral spirits, petroleum spirits, kerosene and the like. A number of synthetic resins may be used including polystyrene, polyvinyl chloride, polysocyanates, polyurethane, polyethylene, and the like.
Various other matrices have been developed to retain lubricating oils as a solid microporous polymer lubricant (MPL) composition. Polyethylene polymer matrices are disclosed in U.S. Pat. No. 3,541,011 to Davis et al. Other matrices are also known, such as the matrix disclosed in U.S. Pat. Nos. 4,486,319 and 4,623,472 to Jamison and Jamison et al., respectively, which disclose a microporous solid ionomer polymer lubricant containing composition having a matrix which may include terpolymers of isobutylacrylate, methacrylic acid and/or polyethylene. Other ionomers reported to be alternately useful include copolymers of ethylene and sodium or zinc salts of methacrylic acid. The polymer matrix may also include other polymers, such as for example, polyethylene, polypropylene, and the like. Other proprietary microporous polymer lubricants are also known such as propriety Micropoly.RTM. lubricants sold by PhyMet, Inc. Springboro, Ohio.
Unfortunately these microporous polymer lubricants do not withstand abrasion, friction and the application of force by hard metal or other objects and can abrade away rapidly upon use in situations where mechanical force or abrasion is applied to the surfaces of such materials.
Such abrasion can be envisioned in the sliding structures for heavy loads disclosed in U.S. Pat. No. 5,290,617 to Mochizuki et al. wherein a solid lubricating material is buried in a sliding surface and an oil reservoir of predetermined capacity is maintained on the reverse side of the sliding surface to provide a source of lubricant which passes through pores of the solid lubricating material to the sliding surface. Nevertheless, abrasion will occur and the sliding surface will wear due to the abrasion resulting from the sliding along the surface.
U.S. Pat. No. 4,177,727 to Cooke et al discloses a line printer character chain lubricating device including a piece of flexible, reportedly abrasion-resistance, microporous neutral rubber that is impregnated with a lubricating oil. The mitral rubber is reported to have a smooth convex surface for contacting the character chain. Depressions in nitrile rubber beside the convex surface serve as charging reservoirs for the lubricating oil. Because of the abrasion likely to occur when the character chain passes over the nitrile rubber lubricating surface, "abrasion-resistance" polymer material was necessary for this particular application. In any case, abrasion will still occur as the chain passes over the microporous polymer surface.
It will be appreciated, therefore, that further improvements in lubricating systems are needed to address the need for lubrication to the many systems and devices used in industry today to reduce wear upon expensive capital machinery and the like. The present invention provides solutions to many needs for lubrication of machinery and machine parts such as chains, gears, cables, wire ropes and the like. Environmental and safety considerations are additional factors driving this invention as this applicator eliminates excessive lubrication and resultant slippery work surfaces for employees when application systems are used which apply excessive amounts of lubrication.